TUCSON, Ariz. The cactus ferruginous pygmy owl population in northern Sonora, Mexico, has declined for the seventh year in a row, according to a new study produced by University of Arizona researcher Aaron Flesch. The report’s findings run counter to assertions that pygmy owls are abundant across the border, which was the primary basis for the April 2006 decision to strip the owl of protection under the Endangered Species Act. Conservation groups are currently challenging this decision in court.

“The pygmy owl’s declining status in Mexico, combined with very small numbers in Arizona, shows clearly that the species should have remained an endangered species under the Endangered Species Act,” said Noah Greenwald, conservation biologist with the Center for Biological Diversity.

The study found that pygmy owls in northern Sonora have declined 4.4 percent per year, or 26 percent overall since the year 2000, and concluded that “should this apparent decline continue, recovery strategies that rely on pygmy-owls from northern Sonora and persistence of pygmy-owls in the Sonoran Desert could be jeopardized.”

“The status of the pygmy owl is clearly more precarious now than ever before,” said Jenny Neeley, southwest representative of Defenders of Wildlife. “Without appropriate protections, the very existence of the pygmy owl in the region is in grave doubt.”

Declines of pygmy owls were more severe in regions of northern Sonora with greater intensity of human land use, such as woodcutting and agricultural development. Evidence also suggests that reproductive success was lower during years with low winter rainfall. Given recent findings by the National Research Council that drought in the Southwest may become more common due to global warming, this raises a red flag.

“The combination of habitat destruction and global warming may be the nail in the coffin for the cactus ferruginous pygmy owl in the Sonoran Desert,” said Greenwald. “The Bush administration’s willingness to let the pygmy owl go extinct in Arizona is characteristic of its contempt for the nation’s endangered species.”

Ferruginous pygmy owls are found over a large part of Mexico. Recent genetic studies, however, found that a unique subspecies occurs in Arizona, Sonora and Sinoloa. Within this subspecies, U.S. Fish and Wildlife Service biologists have identified the Sonoran Desert pygmy owl as a unique population worthy of consideration for Endangered Species Act protection. Combined with population studies in the U.S., Flesch’s study indicates that the Sonoran Desert pygmy owl is declining on both sides of the border.

“It is irresponsible to do anything other than take aggressive action to protect these amazing owls,” said Sandy Bahr, conservation outreach director for the Sierra Club’s Grand Canyon Chapter. “This research confirms that. We would all like to see the pygmy owls continue to inhabit and enrich the Sonoran Desert.”

For questions about this study, contact Aaron Flesch, University of Arizona, (520) 730-4656.

The Center for Biological Diversity is a nonprofit conservation organization with more than 32,000 members dedicated to the protection of imperiled species and habitat.